Viessmann Vitotronic 100 GC1 Quick guide

Installation and
Service Instructions
for use by heating contractor
Vitotronic 100, Model GC1
Digital boiler control unit
VITOTRONIC 100, GC1
Certified as a component part
of Viessmann boilers only
Read and save these instructions
for future reference.
IMPORTANT
1
Please file in Service Binder
5351 338 v1.8 10/ 013

General information
Safety, Installation and Warranty Requirement
Please ensure that this manual is read and understood before commencing installation. Failure to comply with the issues
listed below and details printed in this manual can cause product/property damage, severe personal injury, and/or loss of
life. Ensure all requirements below are understood and fulfilled (including detailed information found in manual subsections).
Licensed professional heating
contractor
The installation, adjustment, service,
and maintenance of this equipment
must be performed by a licensed
professional heating contractor.
Please see section
entitled “Important
Regulatory and
Installation
Requirements.”
Product documentation
Read all applicable documentation
before commencing installation. Store
documentation near boiler in a readily
accessible location for reference in the
future by service personnel.
For a listing of
applicable literature,
please see section
entitled “Important
Regulatory and
Installation Requirements.”
Advice to owner
Once the installation work is complete,
the heating contractor must familiarize
the system operator/ultimate owner
with all equipment, as well as safety
precautions/requirements, shut-down
procedure, and the need for
professional service annually before the
heating season begins.
Warranty
Information contained in
this and related product
documentation must be
read and followed. Failure
to do so renders warranty
null and void.
5351 338 v1.8

General information
3
Safety, Installation and Warranty Requirement (continued)
Safety Terminology
Take note of all symbols and notations intended to draw attention to potential hazards or important product information.
These include ”WARNING”, ”CAUTION”, and ”IMPORTANT”. See below.
Helpful hints for installation, operation
or maintenance which pertain to the
product.
5351 338 v1.8
Indicates an imminently hazardous
situation which, if not avoided, will
result in death, serious injury or
substantial product / property damage.
DANGER
Indicates an imminently hazardous
situation which, if not avoided, could
result in death, serious injury or
substantial product / property damage.
WARNING
Indicates an imminently hazardous
situation which, if not avoided, may
result in minor injury or product /
property damage.
CAUTION
IMPORTANT

4
Vitotronic 100, GC1
For installation on Viessmann Applicable to the following control units:
boilers only. Part No. 7134 553/7134 554/7511361, from Serial No. 7143 00 
This document describes the Vitotronic 100, GC1 as used in
a single-boiler application and a multi-boiler system with an external building
automation system.
These instructions are not required for the Vitotronic 100, GC1 used in multi-boiler
systems with the Vitocontrol-S, VD /CT3/CM .
Product Information
5351 338 v1.8

Index
5
Page
General Information
Safety Instructions and Warranty Requirements ................................
Product Information 4 ........................................................................................
Heating System Types
Overview 7 ..............................................................................................................
Circuit Diagrams 1 to 15 8 .............................................................................
Installation
Mounting the Front Part of the Control Unit (VD /VD A/CT3 only) 37
Opening the Control Unit (VD /VD A/CT3 only) 38 .................................
Control and Junction Box Installation Instructions (CM only) 39 ...........
Mounting the Front Part of the Control Unit (CM only) 40 ......................
Opening the Control Unit (CM only) 41 .......................................................
Overview of Electrical Connections 4 ..........................................................
Overview of Electrical Connections (VD /VD A/CT3 only) 43 .............
Overview of Electrical Connections (CM only) 44 ...................................
Routing and Strain Relief of Cables 45 .........................................................
Inserting the Boiler Coding Card 46 ...............................................................
Setting of the Fixed High Limit (if required) 47 .........................................
Setting of the Adjustable High Limit (if required) 48 .............................
Sensor Connection 49 .........................................................................................
Connection of the Boiler Temperature Sensor 50 .....................................
Connection of the DHW Tank Temperature Sensor 51 ..........................
Connection of the Return Temperature Sensor 5 ...................................
Connection of the Flue Gas Temperature Sensor 53 ..............................
Connection of the Pumps (VD /VD A/CT3 only) 54 ...............................
Connection of the Pumps (CM only) 55 .....................................................
Connection of Return Mixing Valve or
Isolation/Modulating Valve (VD /VD A/CT3 only) 56 ..............................
Connection of Return Mixing Valve or
Isolation/Modulating Valve (CM only) 57 ....................................................
Making Space for Accessory Adaptors on the Din Rail (CM only) 58 .
Vitotronic 100, GCI with 30% LTP Package 59 ......................................
Connection of External Controls 60 ...............................................................
Connection of External Controls (VD /VD A only) 6 ...........................
Connection of External Controls (CT3 only) 64 ..........................................
Connection of Combustion Air Device (VD /VD A/CT3 only) 66 .......
Connection of Combustion Air Device (CM only) 67 .............................
Connection of Combustion Air Device 68 ....................................................
Connection of Combustion Air Device on Multiple Boiler Systems 69
Connection of Single Air Device on Multiple Boiler Systems 70 ........
Connection of Combustion Air Damper 71 ..................................................
Gas Flue Temp. Sensor (Optional for CM equipped with
SS Flue Collector) 7 ............................................................................................
Connection of Low Water Cut-off Device (VD /VD A/CT3 only) 73
Connection of Low Water Cut-off Device (CM only) 74 ......................
Connections to Terminal aBÖ (VD /VD A/CT3 only) 75 ........................
Connection of the Compiled Failure Alarm Indicator
(VD /VD A/CT3 only) 76 ......................................................................................
Connection of the Compiled Failure Alarm Indicator (CM only) 77 .
Burner Connection, Burner Control Wiring (VD /VD A/CT3 only) 78
Power Supply Connection to Boiler Control (VD /VD A/CT3 only) 8 . .
Burner Connection, Burner Control Wiring (CM only) 83
5351 338 v1.8

6
Start-up
Procedure (overview) 84 .....................................................................................
Steps 85 ....................................................................................................................
Scanning Service Information
Overview of Service Levels 9 ........................................................................
Temperatures, Boiler Coding Cards and Scans 93 ..................................
Scanning Service Information 97 ....................................................................
Scanning and Resetting the Service Display 98 .......................................
Troubleshooting
Troubleshooting Steps 99 ..................................................................................
Diagnosis 100 ............................................................................................................
Functional Description
Boiler Temperature Control 105 .........................................................................
Heating Circuit Control 106 ..................................................................................
DHW Tank Temperature Control 106 ..............................................................
Additional Information
Overview 108 .............................................................................................................
Technical Data 109 ...................................................................................................
System Components 109 .....................................................................................
Coding 1 115 ..............................................................................................................
Coding 117 ..............................................................................................................
Wiring Diagrams 1 5 ..............................................................................................
Parts List 130 .............................................................................................................
5351 338 v1.8

Heating system types
7
Overview
Circuit
diagram
System type Boiler Key features Page
11 Single-boiler
system Vitorond 00, VD A With Therm-Control, single-boiler with 3-way mixing valve 8
1Multi-boiler
system Vitorond 00, VD A With Therm-Control, multi-boiler with 3-way mixing valve 10
13 Single-boiler
system Vitorond 00, VD Shunt pump for elevating the return temperature 11
14 Single-boiler
system Vitorond 00, VD Shunt pump and return valve for elevating the return temperature 13
15 Multi-boiler
system Vitorond 00, VD Shunt pump for elevating the return temperature for each boiler 16
16 Multi-boiler
system Vitorond 00, VD Common supply pump and low-pressure manifold 17
17 Multi-boiler
system Vitorond 00, VD Return valve for return temperature protection 19
8 Multi-boiler
system Vitorond 00, VD Low-loss header and return valve for elevating the return temperature 1
9 Single-boiler
system Vitocrossal 300 Several heating circuits and one mixing valve heating circuit 3
10 Single-boiler
system Vitocrossal 300 Several heating circuits and one mixing valve heating circuit 5
11 Multi-boiler
system Vitocrossal 300 Several heating circuits and one mixing valve heating circuit 7
1 Multi-boiler
system Vitocrossal 300 and Vitorond 00 Several heating circuits, one mixing valve heating circuit and Vitorond with shunt pump 9
13 Multi-boiler
system Vitocrossal 300 and Vitorond 00 Return valve, several heating circuits and one mixing valve heating circuit 31
14 Single-boiler
system Vitocrossal 00 Several heating circuits and one mixing valve heating circuit 33
15 Multi-boiler
system Vitocrossal 00 Several heating circuits and one mixing valve heating circuit 35
5351 338 v1.8

Heating system types
8
Circuit Diagram 1
Single-boiler system with Therm-Control and three-way mixing valve
in conjunction with Vitorond 00, VD A
AHeating circuit with mixing valves
BDHW tank
Plug
!Outdoor temperature sensor
(only for Vitotronic 300)
?M Flow temperature sensor,
mixing valve (only for the
Vitotronic 300)
?M3 Flow temperature sensor,
mixing valve (only for
Vitotronic 300)
§Boiler water temperature
sensor
%DHW tank temperature sensor
(accessory for the Vitotronic
100)
aJATherm-Control temperature
sensor
sÖM Heating circuit pump, mixing
valve (only for Vitotronic 300)
sÖM3 Heating circuit pump, mixing
valve (only for Vitotronic 300)
sÖA1 Closing the mixing valves with
external heating circuit control
units
sA DHW primary pump
sK DHW circulation pump (only
for the Vitotronic 300)
fÖ Power supply, 1 0 VAC
60 Hz
Install the main isolator in
accordance with regulations
fA Burner (stage 1)
gSM Mixing valve motor (only for
Vitotronic 300)
gSM3 Mixing valve motor (only for
Vitotronic 300)
lÖ Burner
(burner stage / mod.)
aVD/aVH External connections
Please refer to t e control
manual Vitotronic 300 GW2.
5351 338 v1.8

Heating system types
9
Circuit Diagram 1 (continued)
sÖ A1 Close mixing valves
AContactor relay, field supplied
BHeating circuit controls
connected downstream
Switch contact closed: signal
for ”close mixing valve”.
Wiring diagram
Wiring of the Therm-Control in heating
systems with heating circuit control units
are not connected to the boiler control
unit via the LON.
Required coding:
Change “4C” to “ ” - use the plug-in
connector 0 A1 to close the
downstream mixing valve. Change “0D”
to “1” - the Therm-Control acts on the
mixing valve of the downstream heating
circuits (for Vitotronic 00 and 300,
delivered condition).
5351 338 v1.8

Heating system types
10
Circuit Diagram
Multi-boiler system with Therm-Control and three-way mixing valve
in conjunction with Vitorond 00, VD A
LON LON connection (available connections with terminator)
AHeating circuit with mixing valves
BDHW tank
Plug
!Outdoor temperature sensor
(only for Vitotronic 300-K)
?Flow Flow temperature sensor,
common heating flow (only for
the Vitotronic 300-K)
?M Flow temperature sensor,
mixing valve (only for the
Vitotronic 300-K)
?M3 Flow temperature sensor,
mixing valve (only for the
Vitotronic 300-K)
?Flow temperature sensor
Vitotronic 00-H
§Boiler water temperature
sensor
%DHW tank temperature sensor
(only for Vitotronic 300-K)
aJATherm-Control temperature
sensor
sÖM Heating circuit pump, mixing
valve (only for Vitotronic
300-K)
sÖM3 Heating circuit pump, mixing
valve (only for Vitotronic
300-K)
sÖ Heating circuit pump Vitotronic
00-H
sK DHW circulation pump (only
for the Vitotronic 300-K)
fÖ Power supply, 1 0 VAC
60 Hz
Install the main isolator in
accordance with regulations
fA Burner (stage 1)
gSA1 Motorized butterfly valve
gSM Mixing valve motor (only for
Vitotronic 300-K)
gSM3 Mixing valve motor (only for
Vitotronic 300-K)
gSM3 Mixing valve motor, Vitotronic
00-H
lÖ Burner
(burner stage / mod.)
aVD/aVH External connections
Please refer to t e control
manual for t e Vitocontrol-S,
VD2/CT3.
5351 338 v1.8

Heating system types
11
Circuit Diagram 3
Single-boiler system with shunt pump for elevating the return temperature
in conjunction with Vitorond 00, VD
ABoiler with Vitotronic 100, GC1
BDomestic hot water tank
CHeating circuit with mixing valve
Plugs
§Boiler temperature sensor
%DHW tank temperature sensor
(accessory)
aJ ATemperature sensor T1
aJ BTemperature sensor T
sÖ A1 Close mixing valves with
external heating circuit
controls
sA DHW pump
sL Shunt pump
fÖ Power supply connection,
1 0 VAC
fA Burner (1st stage)
lÖ Burner ( nd stage/modulating)
aVD Connection of external
equipment (see page 60)
aVH Connection of external
equipment (see page 60)
*1
On t e Vitorond t e boiler supply and return are at t e rear of t e boiler.
5351 338 v1.8
B
C C
A
90 41 40
146 143
3
17A
17B
T1
T
*1
9
5
1
A1 0

Heating system types
1
Circuit Diagram 3 (continued)
Possible applications
Heating systems with manifold
arranged close to the boiler. The boiler
water supply is required to be reduced.
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
heating contractor to check that this
recommendation is complete and fully
functional. Three-phase equipment
must be connected via additional
power contactors.
When the return temperature falls
below the required minimum value,
the temperature sensor T switches
on the shunt pump. If the minimum
return temperature is not reached
despite raising the return temperature,
the supply must be reduced by at
least 50% via the temperature
sensor T1.
The shunt pump must be sized so
that bypassed water accounts for
approx. 30% of the total supply rate
of the boiler.
Temperature sensor T1
Wiring of the temperature sensor T1
in heating systems with heating
circuit control units which are not
connected via the LON BUS to the
boiler control unit.
Coding required: ”4C: ” – use plug
sÖ for closing the mixing valves of
the heating circuits connected
downstream.
sÖ A1 Close mixing valves
AContactor relay, field supplied
BHeating circuit controls
connected downstream
Switch contact closed: signal
for ”close mixing valve”.
Available system accessories
Flue gas temperature sensor
Coding of
system type
Change required Automatic change
00: 1 ––– With DHW tank:
Coding is automatically changed to ”00: ”
0 : 1 Set coding ”0 : ” for operation with
modulating burner
–––
03: 0 Set coding ”03: 1” for oil-fired operation
(re-setting is not possible)
–––
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4b: 0 ––– Connection of the temperature sensor T at
plug aJB;
Coding is automatically changed to ”4b: 1”
5351 338 v1.8
IMPORTANT

Heating system types
13
Circuit Diagram 4
Single-boiler system with shunt pump and return valve for elevating the return temperature
in conjunction with Vitorond 00, VD
ABoiler with Vitotronic 100, GC1
BDomestic hot water tank
CHeating circuit with mixing valve
Plugs
§Boiler temperature sensor
%DHW tank temperature sensor
(accessory)
aJ ATemperature sensor T1
aJ BTemperature sensor T
sA DHW pump
sL Shunt pump
fÖ Power supply connection,
1 0 VAC
fA Burner (1st stage)
gS A1 Mixing valve motor for raising
the return temperature
lÖ Burner ( nd stage/modulating)
aVD Connection of external
equipment (see page 60)
aVH Connection of external
equipment (see page 60)
*1
On t e Vitorond t e boiler supply and return are at t e rear of t e boiler.
5351 338 v1.8
B
C C
A
90 41 40
146 143
3
17A
17B
T1
T
*1
9
5
1
A1 5

Heating system types
14
Circuit Diagram 4 (continued)
Possible applications
Heating systems in which there is no
facility for making modifications or
adjustments to the heating circuits
connected downstream, e.g. old
systems or market gardens.
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
heating contractor to check that this
recommendation is complete and fully
functional. Three-phase equipment
must be connected via additional
power contactors.
When the return temperature falls
below the required minimum value,
the temperature sensor T switches
on the shunt pump. If, as a result,
the required minimum return
temperature is not reached, the return
valve is proportionally closed via the
temperature sensor T1 and the
minimum return temperature is
assured.
Available system accessories
Flue gas temperature sensor
Coding of
system type
Change required Automatic change
00: 1 ––– With DHW tank:
Coding is automatically changed to ”00: ”
0 : 1 Set coding ”0 : ” for operation with
modulating burner
–––
03: 0 Set coding ”03: 1” for oil-fired operation
(re-setting is not possible)
–––
0C: 4 Set coding ”0C: 1” for continuous
return temperature control
–––
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4b: 0 ––– Connection of the temperature sensor T at
plug aJB;
Coding is automatically changed to ”4b: 1”
5351 338 v1.8
IMPORTANT

Heating system types
15
Circuit Diagram 5
Multi-boiler system with shunt pump for elevating the return temperature for each boiler
in conjunction with Vitorond 00, VD
ABoiler with Vitotronic 100, GC1
BDomestic hot water tank
CHeating circuit with mixing valve
Plugs
§Boiler temperature sensor
aJ ATemperature sensor T1
aJ BTemperature sensor T
sL Shunt pump
fÖ Power supply connection,
1 0 VAC
fA Burner (1st stage)
gS A1 Motorized isolation valve
lÖ Burner ( nd stage/modulating)
aVD Connection of external
equipment (see page 60)
aVH Connection of external
equipment (see page 60)
5351 338 v1.8
B
CC
A A
3
17B
90
41
40
146 143
5 A1
T1
17A
T
9
3
17B
90
41
40
146 143
5 A1
T1
17A
T
9

Heating system types
16
Circuit Diagram 5 (continued)
Possible applications
Heating systems with manifold
arranged close to the boiler. The boiler
water supply is reduced via the
motorized isolation valve.
On multi-boiler systems without the
Vitotronic 333, the cascade and DHW
tank control must be activated by a
building automation system.
T is circuit diagram represents a
recommendation only. It is t e
responsibility of t e customer and/or
eating contractor to c eck t at t is
recommendation is complete and fully
functional. T ree-p ase equipment
must be connected via additional
power contactors.
When the return temperature falls
below the required minimum value,
the temperature sensor T switches
on the shunt pump. If the minimum
return temperature is not reached
despite raising the return temperature,
the supply must be reduced by at
least 50% via the temperature
sensor T1, through the isolation
valve or the heating circuit controls.
The shunt pump must be sized so
that bypassed water accounts for
approx. 30% of the total supply rate
of the boiler.
The boiler is assured optimum
protection in conjunction with control
of the heating circuits via the
Vitotronic 050 connected to the
boiler control unit. No further
protective measures are required on
site.
Temperature sensor T1
Wiring of the temperature sensor T1
in heating systems with heating
circuit control units which are not
connected via the LON BUS to the
boiler control unit.
Coding required: ”4C: ” – use plug
sÖ for closing the mixing valves of
the heating circuits connected
downstream.
sÖ A1 Close mixing valves
AContactor relay, field supplied
BHeating circuit controls
connected downstream
Switch contact closed: signal
for ”close mixing valve”.
Available system accessories
Flue gas temperature sensor
Coding of
system type
Change required Automatic change
01: 1 Set coding ”01: 3” for multi-boiler system
with external cascade control via switch
contacts
–––
0 : 1 Set coding ”0 : ” for operation with
modulating burner
–––
03: 0 Set coding ”03: 1” for oil-fired operation
(re-setting is not possible)
–––
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4b: 0 ––– Connection of the temperature sensor T at
plug aJB;
Coding is automatically changed to ”4b: 1”
5351 338 v1.8
IMPORTANT

Heating system types
17
Circuit Diagram 6
Multi-boiler system with common supply pump and low-pressure manifold
in conjunction with Vitorond 00, VD
ABoiler with Vitotronic 100, GC1
BDomestic hot water tank
CHeating circuit with mixing valve
DCommon supply pump
Plugs
§Boiler temperature sensor
aJ ATemperature sensor T1
fÖ Power supply connection,
1 0 VAC
fA Burner (1st stage)
gS A1 Motorized isolation valve
lÖ Burner ( nd stage/modulating)
aVD Connection of external
equipment (see page 60)
aVH Connection of external
equipment (see page 60)
5351 338 v1.8
B
3
17A
90
41
40
146 143
5 A1
A A
3
17A
90
41
40
146 143
5 A1
T1 T1
CC
D

Heating system types
18
Circuit Diagram 6 (continued)
Possible applications
Where the manifold is arranged in
distant substations (> 0 m). The
heat transferred to the heating circuits
is required to be reduced.
On multi-boiler systems without
Vitotronic 333, the boiler staging and
DHW tank control must be activated by
a building automation system.
The common supply pump is activated
by the master control of the building
management system. It must be
switched on when a boiler is engaged.
T is circuit diagram represents a
recommendation only. It is t e
responsibility of t e customer and/or
eating contractor to c eck t at t is
recommendation is complete and fully
functional. T ree-p ase equipment
must be connected via additional
power contactors.
When the return temperature falls
below the required minimum value,
the mixing valves are partially or fully
closed via the temperature sensor T1.
The common supply pump must be
sized on the basis of 110% of the total
supply Btu/hr output rate of the heating
system.
The boiler is assured optimum
protection in conjunction with control
of the heating circuits via a Vitotronic
050 connected to the boiler control
unit. No further protective measures
are required on site.
Temperature sensor T1
Wiring for reducing the supply via
temperature sensor T1 in heating
systems with heating circuit control
units which are not connected via
the LON BUS to the boiler control unit.
Coding required: ”4C: ” – use plug
sÖ for closing the mixing valves of
the heating circuits connected
downstream.
sÖ A1 Close mixing valves
AContactor relay, field supplied
BHeating circuit controls
connected downstream
Switch contact closed: signal
for ”close mixing valve”
CPower supply connection,
1 0 VAC
DJunction box, field supplied
If an external cascade control unit is
used, the distributor pump must be
connected to the external control unit.
Available system accessories
Flue gas temperature sensor
Coding of system type Change required Automatic change
01: 1 Set coding ”01: 3” for multi-boiler system
with external cascade control via switch
contacts
–––
0 : 1 Set coding ”0 : ” for operation with
modulating burner
–––
03: 0 Set coding ”03: 1” for oil-fired operation
(re-setting is not possible)
–––
0d: Set coding ”0d: 1”
Therm-Control is effective for the mixing
valves of the heating circuits connected
downstream
–––
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
5351 338 v1.8
IMPORTANT

Heating system types
19
Circuit Diagram 7
Multi-boiler system with return valve for return temperature protection
in conjunction with Vitorond 00, VD
ABoiler with Vitotronic 100, GC1
BDomestic hot water tank
CHeating circuit with mixing valve
Plugs
§Boiler temperature sensor
aJ ATemperature sensor T1
sL Boiler circuit pump
fÖ Power supply connection,
1 0 VAC
fA Burner (1st stage)
gS A1 Return valve
lÖ Burner ( nd stage/modulating)
aVD Connection of external
equipment (see page 60)
aVH Connection of external
equipment (see page 60)
5351 338 v1.8
B
3
17A
A A
3
17A
T1
CC
90
41
40
146 143
5 A1
9
T1
90
41
40
146 143
5 A1
9

Heating system types
0
Circuit Diagram 7 (continued)
Possible applications
E.g. old systems or systems in market
gardens and/or systems in which there
is no facility for making modifications
or adjustments to the heating circuits
connected downstream.
The cascade and DHW tank control
must be activated by a building
automation system.
T is circuit diagram represents a
recommendation only. It is t e
responsibility of t e customer and/or
eating contractor to c eck t at t is
recommendation is complete and fully
functional. T ree-p ase equipment
must be connected via additional
power contactors.
When the return temperature falls
below the required minimum value,
the 3-port mixing valve on the boilers
is proportionally closed via the
temperature sensor T1, thereby
assuring protection of the boiler.
The boiler and the heating circuits
downstream are hydraulically
decoupled. The supply temperature
is controlled via the common
temperature sensor.
Available system accessories
Flue gas temperature sensor
Coding of
system type
Change required Automatic change
01: 1 Set coding ”01: 3” for multi-boiler system
with external cascade control via switch
contacts
–––
0 : 1 Set coding ”0 : ” for operation with
modulating burner
–––
03: 0 Set coding ”03: 1” for oil-fired operation
(re-setting is not possible)
–––
0C: 4 Set coding ”0C: 1” for continuous return
temperature control
–––
4A: 0 ––– Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to ”4A: 1”
4d: 1 Set coding ”4d: ” for boiler circuit pump
at plug sL
–––
5351 338 v1.8
IMPORTANT